Telephone-exchange system



W. H. HARRISON.

TELEPHONE EXCHANGE SYSTEM.

APPHCATION FILED APR. 11. 1918.

l ,330,467. Patented Feb. 10, 1920.

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W. H. HARRISON.

TELEPHONE EXCHANGE SYSTEM.

APPLlCATlON FILED APR-11.1918.

Patented Feb. 10, 1920.

3 SHEETSSHEET 2.

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Patented Feb. 10,1920.

3 SHEETSSHEET 3- WILLIAM H. HARRISON, or BROOKLYN, new-roan, ASSIGNOB re wiisrnaiv niinornio COMPANY, INCORPORATED, or new YORK, N. Y., AOORIORATION 0F,1\IEW-YO BK-,;

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To all whom it mag concern: I a Be it knownthat I, WILLIAM H. rheumsoN, a citizen of the United States, residing at Brooklyn. in the county of Kings,'State of New York, have invented certain new -.and useful Improvements in Telephone-EX; 7,

association :of an operators telephone set Wltll the link circuits employed for interconnecting telephone lines.

In accordancev with one with i'neans responsive to the actuation of the listening switch of'the link circuit, when one of the two supervisory relays thereof is energized and the other is deenergized, thereby to connect the Operators telephone set withthe link circuit. 7 I i For a more complete understanding of this invention, reference should helhad to the following description considered connecv tion with the accompanying drawings, in

which Figures 1, 2 and 3, when placed end to end in the order named, illustrate one embodiment of the present invention.

Referring to the drawihggthere is shown a two-way trunk circuit C extending-from the originating or information operators desk or position X to a chief operators desk Y. A cord circuit B providedat the infer ination' operators desk X may heeniployed to connect the information operators telephone set with the trunk circuit C. Atw way trunk circuit extends from the chief operators desk Y to the nianagerls orassistant inanagers desk Z. A 1111i; circu t D =vided at the chief operators desk Y may o er either tminkcircuit, in initiating calls outgoing over either trunk c rcuit, or in completing connections between the information desk X'and the inanagers deskZ. v he"trunk Cir-3111 6 E terminates iii a key or switch the nianagers desk, by the actua- '-ion of which calls may be answered or 'iated. h

and usually are provided with multiple feature of this invention an operators position s QIOVldGCl:

p lt will he understood of course at thej jaclnended trunkfcircuits may he s Specification of Letters Patent. Application filed Apr-i111, 1913. s minal semis.

for convenience, These trunk circuits may very properly be considered sis-telephone lines which terminate at the chief operators desk Y. will be understood too,.thatja 1.

plurality of trunk circuits siinilar to-"C and B may be 'employ'ed, only one Of each-being shown nie'relyf for convenience? The appa v ratus shown to the left of the dottedline l lis associated with the originating'f'or.

information OPQflttOIfS POSlfiOH or deskRX,- I that shown between the dotted lii es4+4 and 5-5 'i'v ith the chief operators'deskY, and

tliatshowii to the right of the dotted line? with the nianagefis or assistant mam;

agers desk Z. In Fig.2, the" apparatus shown above the dottedline is-co'niinon-to a plurality of'link circuits.

tion will be fully understood from a do? closedtherein;v

The information. operator X desiring V to connnunicate with the chief'op'eratorY actuates listeningkey 6' and'inserts plug-[of eord cir'ouit'B into jack 8 of 'the'trunk'ci'rcuit C, thereby causing the operation of re} lllithtl is brief description of the draw- I .ingsiii'rn nd, it is thought that the invertscriptionofthe operationof the systenidis causes lainp"13 to jbe lighted over acircuit from battery through the upper contact of relay l' OQup'per contact of relay 9 and the lamp 13' to -ground. Relay 12 'is energized by the operation of relay 10 to open the'c'i'rv cuit of and preventthe lighting of 'lamp'21' when the chief operator answers. The lighting-of tl e'l ainp 13 serves as a line signail to the chief operator. The operation of to the ring'and tip conductors respectively relay "10 also saunas battery and ground of the chief opferatons desk end 'ofthetrunk circuit C for purposes 'Ofsupervision.

he chief operator, observing the lighted of the lainplinsertsanswering v of the cord circuit D into acka'lo' of the trun circuit C, whereupon relay 14f oncrateso era circuit,fronih'attery through I ,e contactsjof the plug 15 and the'jack' stance l7, contact 18 of listening: key l9,

iio

the trunk circuit C, and causes the operation of relay 9. "Relay 9, in operating, opens the i circuit of and extinguishes the lamp 13. Re-

lay 12 is now. locked up over a circuit from the cord circuit D be disconnected before the cord'circuit B. 7 Both relays Sand 12 re--. main locked up until bothjcord circuits have been disconnected. Theinsertion of the plug 1.51into the jack$16also causes the operation of supervisory relay 27 of the cord circuit D over a circuit from battery through theupper contact of-relay 10, ring contactsof the r jack 16 and the plug 15, thewinding oi.-

,supervisory relay 27, contact 2e ofthe listen lng key19, retardation coil 23, tip contacts of the plug 15 andthe jaclr16 and the lower contact of relay 3101 to ground. Supervisory 'tac-tof relay 28 to ground.

relay 27 ,1 in operating, opensa, contact in circuit with the answering supervisory lamp 73 1, thereby preventingthe lighting'thereofwhen the calling end of the cord circuit is connected with trunk circuit E.

The chief operator may now actuate, listening-key 19 to connect the telephone set with the talking strands of the cordicin cuit D. Upon the actuation of the listening key 19, relay'20 operates over a circuit from battery through-the winding of relay 20,

contact 25 of the listening key 19, sleeve contacts of the plug 15 and the jack 16 and the winding of relay 14 to ground; Sincecontact 25 makes before contact '18; breaks relay 14- is not deenergized when the listening key 19 1S actuated. Relay 20, re operat ng opens a contact incircuit with busy test relay 47, thereby disconnecting this busy test relay from the tip or testing conductor asso'ciat'e'd'with the answering end of the cord circuit. Uponthe actuation'of the listening key'19 the windingsof retardation :coil 31 andrelay 28 are connected in bridge 'of'the talking conductors of the cord circuit D in substitution of the winding of the retardation coil 23. Supervisoryrelay 27' remains operated, and relay;28 operates. Ihe operating circuit for relay 28 may be traced frombattery through the uppercontact of lrelay 10, ring contacts of the jack l6fand the plug 15, winding of supervisory relay 27, contact'29 of li tening key 19, lowernormal contact of ringing key. 30, winding of relay 28- and lower winding of retardation coil 31in parallel. upper winding of retardation COll 31. upper normal contact of ringmg key '30, contactv 32 of listening key 19,

ringin current, are avoided.

tip contacts of the plug 15 and the jack 16 and the lower contact of relay 10 to ground. Relay 28, 1n operating, establishes energizing circuits for a fast-operating and slowreleasing relay a0 and a slow-operating relay ll. -The energlzlng circuit for relay 4:0. is from battery through thewindingof -re a to normal contact of rela 41 lefty u a 1 y hand normal Contact of relay 42and contact r of relay 28 to ground, while the energizing circuit forrelay 41 is'from battery through 42 Slow-operating relay 11, upon attracting its armatures, opens, the circuit of relay 40, and closes a contact in the energizing circuit of relay e2, so that upon therelease of the slow-releasing relay eO, relay 4E2 is operated over a circuit from a battery through the winding of relay l2, contact of relay 40, and

left-hand contact of relay 5l1 to ground. Relay 4:2, in operating, closes its left-hand alternate contact, thereby establishing a locking circuit for itself through the corn The opening of the left-handnormalcontact of'rela'y 42 releases-relay 4E1. Relays 4O andw' ll cannot be energized again until after the release of relay 42. Relay l2,in operating, also closes 7 its right-hand and middle alternate contacts, thereby connecting the operators telephone set with the talking strands of the cord circuit D. The chief operator is now connected with the information operator;

While the delay 'inxthe connection of the operators telephone set'with the talking circuit is, of no particular value when answering a call over a trunk circuit to the outgoing end i'of which is connected. a link circuit not equippedfor autoinatieringing,

still itfis of considerahle value when answerin a call over a trunk circuit to the 7B. outgoing end of which is connected a link circuit equipped for automatic ringing, in which case the usual severe, clicks in the receiver, due to the disconnection of the p The chief operator" may now converse with the information operator to whom information as desired inay be furnished. 1f

the chief operator is not able. to furnish all i of the inforn'iation desired or shouldthe information operator wish to converse withv the manager, the chief operator restores the listening lrey 19 to normal positionand inserts plug 43 of. thecord circuit D into jack 4 of the trunk circuit .E. Upon the re toration of thelisteningfkey 19, relays, 20, 28 and 42 release, whilethe insertu'ufiof the plug 4-3 into the jack 14 causes the. operation 'of relays and 50 over a circuit flOlllbdlG tery through'the winding of relay 45,

60 normal position.

sleeve contacts of the plug'43 and the jack and the winding of relay 50 to groundL "Relay 45, in operating, disconnects the busy :tip strand of the cord circuit -D, and causes the lighting ,of calling" supervisory lamp 48 over a circuitfrom battery through the lamp 48,:normal contact of calling supervisory relay 49 and lower alternate contact of relay 45 to ground. Relay 50, .in operating, lights a lamp 51 at the managers desk over a circuitfrom batterythrough the up- .per contact of relay 50, the upper contact of relay 52 and-the lamp 51 to ground. Relay 50 in operating also causes the energization of relay 53. which opens its upper contact in circuit with a lamp 54, to prevent the lighting thereof when the manager answers. 'The manager observing thelighted condition of the lamp 51- actuates listening key '55, whereupon relays 5.6 and 57 operatein parallel over a circuit which includes the lower contact of the listening key 55. Re-

lay ;56,"in operating, causes the operation'of relay 52 over a circuit from battery through the windingof relay 52 and the upper contact of relay 56 to ground, The operation "of relay 52 opens the circuit of and ex ao tinguishes thelalnp 51. .rRelays 52xand 53 remain locked up until the plug 43 is with drawn from the jack 44 and the listening key 55 is restoredto normal position. Pe lay 56, in operating, also connects talking battery to the trunk circuit E and causes the operation of calling supervisory relay 49 over a circuit from battery through the lower contact of relay 56, repeating coil 'winding '60, ring. contacts of the jack 44 40 and the plug 43, the winding-of the calling I supervisory relay 49, repeating coil winding 61, resistance 62, repeating coil win,ding 63, upper alternate contact of relay 45, tip contactsof the plug 43 and the jack 44, 45' repeating coil winding 64 and the upper contact of relay 56 to ground. Calling supervisory relay 49 in operating opens the circuit of and extinguishes the calling supervisory lamp 48, which indicates to the chief 50 operator that. the manager has answered. Snice-the operation of relay 57 connected the managerstelephone set with the trunk circuit 'E, the manager 'may now converse with the information operator. r

6 At the conclusion of the conversation ho tween the information operator and the manager, the information operator withdraws the plug 7 from the jack 8 and the manager restores the listening key to The withdrawal of the plug 7 from the jack 8 causes the release of relay 10, which disconnects battery and ground from-the chief operators desk end of the trunk circuit C, whereupon answering .supervisory relay .27 .ofthe cord circuitD and lower vvcontactcf relay 45 to.-ground.,

The restoration of the listening key to normal position causes the deenergization'of.

relays 56 and 57 The deener 'izationlof re lay 56 disconnects batteryand ground from" the chief operators desk end of thetrunk circuit E, whereupon the calling supervisory relay 49 of the cord circuit D releases; The

release of relay 49causesthe calling supervisory lamp 48to be lighted. f a

r The, lighting of the 4 two supervisory lamps '84 and 48 serves as a disconnect signal to the chief operator who may withdraw the j plugs, from the acks, restoring all 'ap- 7 parat-us to. normal condition. I

Should the manager, at the conclusion of I the conversation with the information operator ancllbefore the chief operator has with drawn the plug 43'fron1the jack-44, wlsh to converse with the chief o erator the listen ing key 55 is repeatedly actuated to open- .and close its contacts, thereby to cause the intermittent lighting of the calling, supervisory lamp 48 which serves as aisignalf to -thelchiefoperator.- ;After so actuating the listening key 55 inthis mannelggthe mane 'ager leaves thekey, actuatedso that the rel'ays 5 6, 57 and, 49ers operated. Since 1 the information operator has-already withdrawn relay 45 to ground. The lamp 48 is not lighted overthls circult, but the answering supervisory lamp 34'rema1ns lighted.

.lhe chief operator, having noted the inthe plug 7 from thekjack 8, answering superi I visory relay 27 1S- deenerglzed so that relay p ce I of relay 27 and lower alternate contact of 2 termittent lighting ofthe calling supervisory lamp 48 while the answering supervisory lamp 34 is continuously lighted, recognizes:

this as a signal that the manager-1s -,signal-.

ing, and 'actuates the listening key 19. Upon the actuation of this listening key, energiz- 1 h circuits are established for the quick-operating and slow-release relay '40 and the slow-operating relay 41,,which may be traced from batter throu 'h'the windin s of these relays in parallel, left h'and norm a] ,7 contact of relay"v 42, contact "66 of listening key 19 and the contact o f'relay 65 to ground. Relays 40 and 41 ,function as before. de-

scribed to delay theenergization of relay 42 which in operating connectsv the chief operators telephone set with the cord circuit D" and; locks-up through its left-hand alternate contact, contact 66 of listening key 19 --and the contact of relay1 65 to ground The chief operatofis telephone set willlremain connected tothe cord circuit until the-listening key -19 is restored to normal: position,

7 the plugf l3 is Withdrawn ironrthe ack 44, or the manager restores the listening key 55 to normal position.

Should the chief operator initiate a call by employingtheanswering plug 15, the trunk circuit is tested before the plug is inserted in the jack. In making this busy test, the V operator actuates the listening key 19 and then touches the tip of the plug against the sleeve terminal of the jack if the trunk is busy, the busy 'test'r'elay 47 operates over a circuit from battery at the test terminal I 1 of the jack, tip of the plug 15, contacts 232 and 67 of therlistening key 19, right-hand normal contactofrelay 42, contact of relay and the Winding of the busy test relay 47. Busy test relay 47 in operating connects circuit through contacts of the and the listening key. 7

batteryin circuit With the primary Winding of induction coil 68, whereupon a'click is produced in the receiver ofthe operators telephone set. 7 5

What is claimed is I 1. A telephone exchange system coinprising -t vo telepho le lines, a link circuit inter-, connecting the lines, a supervisory signal control relay for each end oi the'link circuit,

an operators telephone set, a listening key, a third relay energized only when one of the supervisory relays isenergized and the other is deenergized, and fourth relay responsive tothe' actuation of the listening key While the third relay is energized toconnect'the operators telephone setivith the link circuit.

2. A telephone exchange system comprising tWo telephone lines, a linkcircuit interconnecting the lines, a supervisory signal control relay for each'end or" the link circuit, anoperators telephone set, a listening key, a third relay, an energizing circuit therefor including a'fconta'ct of one sup-en visory relay When energized and a contact cuit, a listening key, a thirdrelay energized when one of the supervisory relays is energized and the other is deenergizcd, afourth relay, an energizingcircuit theretor 'estalm lished While the listening key is actuated and the third relay'is energized, and an operators telephone set connected with the link fourth rela T 4. A telephone exchange system coinprising two telephone lines, a link circuit interconnecting the lines, a supervisory'signal ,control relay for each end of the link circuit,

an operators telephone set, a listening key, a

third relay hose energi z'a'tion depends upon the energized condition er one supervisory relay an-tithe deenergized condition of the other supervisor rent a fourth rela .tor

l .l a 7 "connecting the operator s telephone set with the link circuit, and an energizing circuit therefor including contacts of the actuated listening key and the energized third relay.

5. A telephoneexchange system c ornprising tvvo t'elephonelines, a link circuit inter- 7 connecting the lines, a supervisory signal control'relay for each end of the link cir-' cuit, an operators telephone set, a listening key, a third relay, an energ zing c rcuit therefor completed through a contact of- 1 one supervisory relay while'energized and a contact of the other supervisory "relay 'While denergized, a fourthrelay for con- -necting the operator7s telephone set with the link circuit, and energizing circuit therefor includ ng contacts of the actuated listening key and the-actuated third relay.

'6, A telephone exchange system. coinpris ing a plurality oi telephone lines terminating in an operators pos tion, a pluralityoi link circuits thereat, one of which intercon iiects two oi the lines, a supervisory signal control relay for each end of the engaged link circuit, an operators'telephone set, a

ssh

listening switch, a relay coinnion to the link] i circuitsoit the operators position for con necting the operators telephone SG'lLWltlL the engaged link circuit, and an energizing circuit for the coininon'relay Whose 'coinpletion depends upon the actuation of the listening switch, the energized condition of one supervisory and the deenergizedi condition oi the other supervisoryrelay.

i. A telephone exchange systeinzcoinpris ing twotelephone lines, a linkcircuit 0011- nected with one of the lines, a relay in the link circuit controlled over the connected line, a local circuit relay energized upon the connection of the link circuit with the other telephone line, a relay in the link circuit controlled over the secondconnected line,

an operator s telephone set, a listening key for the link circuit, a fourth relay in the link circuit Whose .energizatioii depends upon the energized conditionof the. local circuit and second line controlled relays and the deenergized condition 01 the first line controlled relay, and ineans responsive to the actuation of the listening key While the fourth relay is energized to connectthe operators telephone set *ith the link circuit 8. A telephone exchange; systenr -coinprising two telephone lines, a link circuit connected With one or" the lines, a relay in the link circuit controlled over the con nected line, a local-circuit relay energized upon the connectiono'f the link circuit With the other telephone line, a relay in the link circuit controlled over the second connected line, an operators telephone set,a listening key for the link circuit, a fourth relayin the link circuit, an energizing circuit there for including a contact of the local circu t relay, a contact of each line controlled-relay, and means responsive to the actuation or" the listening key while the fourth relay 'is energized to connect thefioperators tele-' phone set with the linklcircuit.

9. A telephone exchange system comprising two telephone lines, a link circuit connected nected line, a local circuit relay energized upon the connection of the l nk circuit with the other telephone line, a relay in the link circuit controlled over the second connected line, an operators telephone set, a listening key for the link circuit, a fourth relay in the link circuit whose energization depends upon the energized condition of the local circuit and second line controlled relay and the deenergized condition of the first line controlled relay, and a relay energized upon the actuation of the 'llS- other telephone line, arelay in the link cir- *ith one of the lines, a relay" .111 the link circuit controlled over the con cuit controlled over the second connected line, an operators' telephone set, a listening key forthe 11111; circuit, afourth relay, in the link circuit energized only While the local circuit relay and the second line c0ntrolled relay are energized, and the first l1ne controlledvrelay is deenergized, a relay forconnectlng the operators telephone setv with the link circuit, and an energizing circuit there-for controlled by the listening key Y and thefourth relay. I

11. A telephone exchange system comininating at an operatbrs' position, a plurality of link circuits there'at, one of the link circuits interconnecting two of the telephone lines, supervisory relays for the engaged link circuit, signaling devices controlled by the supervisory relays, a third relay in the engaged link circuit, an energizing circuit therefor controlled by the supervisory relays, a listening key for the engaged link-circuit, a relay common to thelink circuits, an energizing circuit for the common relay vcontrolled bythe listening switch and the third relay, and an operators telephone set connected with the link circuit through contacts of the common relay and the listening switch.

5 prising a plurality of telephone lines ter- In witness whereof, I hereunto subscribe myname this 5th day of April A; D., 1918.

' WILLIAM H. HARRISON. 

